As YoSoyUnPayaso explains, “The pink fairy armadillo is endemic to Argentina and is nicknamed the sand-swimmer because it is said that it can ‘burrow through the ground as fast as a fish can swim in the sea.'”

In The Amazing Armadillo: Geography of a Folk Critter, authors Larry Smith and Robin Doughty describe the tiny tunneler as “looking like a small guinea pig with pink armor over its head and back.” (Or, y’know, a made-up Pokémon.)

But technically—according to a published research paper titled “Updated Distribution of the Pink Fairy Armadillo“—that pink armor is actually a “flexible dorsal shell [with] about 24 bands … attached to the body only by a thin dorsal membrane.”

If you’ve never seen this Argentinian mammal before, don’t worry: Not many people have.

Coming in at about 5-inches in length, they’re the smallest armadillo species in existence. The nocturnal critters spend most of their lives underground, scientists consider them extremely rare, and they don’t survive well in captivity—so your chances of seeing them in person are next to none.

Even biologists have barely studied them.

On the IUCN’s Red List of Threatened Species, the pink fairy armadillo is currently listed as “Data Deficient,” just one step above “Not Evaluated.”

As the IUCN writes, “… there is little information on the population status of this species, and its biology and ecology are poorly known.”

Efforts to learn more about the the pint-sized pichiciego firsthand have been largely unsuccessful.

In 2011, one of the leading experts on the creatures—armadillologist Mariella Superina—wrote an extremely sad scientific account of her attempt to study a pink fairy armadillo in a sand-filled terrarium.

Instead of extracting one from the wild, she started with a “juvenile male pink fairy armadillo … found by locals in an empty urban lot in a small town of eastern Mendoza Province, Argentina.”

In the first two weeks of the study, Superina found that the creature’s reputation as being “susceptible to stress” was extremely accurate:

“The armadillo remained underground for most of the time. When disturbed, it sometimes emitted a high-pitched screaming, and then ran along the perimeter of its enclosure for several minutes.”

Which, one might imagine, sounded like this:

Superina discovered exactly how sensitive the pink fairy armadillo was when she tried to feed it.

Out of all the foods she tried to get the creature to eat, it rejected 21 different meal options, tried 4 of them only once, and repeatedly ate just 3 types of food: a prepared insect meal (if mixed with other ingredients), “avocado shells with rests of flesh,” and watermelon.

(Other species of armadillo are far less picky—such as the giant armadillo, which BBC Wildlife Magazine reports “is said to dig in cemeteries to feed on corpses.” Yikes.)

Unfortunately, despite finding a few foods he liked, the subject of Superina’s study did not survive captivity:

“The pink fairy armadillo was found dead on October 11, 2009, approximately 25 cm below the surface. The reasons for its death remain unknown.”

Perhaps this subterrestrial species is better left alone in the wild, far away from humans trying to hold it captive in a little glass box.